NSP - Fertilizer Specifications
 

Definitions

Many prefixes such as mineral, inorganic, or chemical are often used to describe fertilizers and these are used interchangeably.
Fertilizer grade is an expression referring to the legal guarantee of the available plant nutrients expressed as a percentage by weight in a fertilizer, e.g. a 12-32-16 grade of NPK complex fertilizer indicates the presence of 12 % nitrogen (N), 32 % phosphorous (P2O5) and 16 % potash (K2O). On a fertilizer bag, the NPK content is always written in the sequence N, P2O5, K2O.

Fertilizers are classified as

  • Straight fertilizers: These contain one of the 3 major nutrients N, P or K.
  • Compound /complex fertilizers: These contain at least two out of the three major nutrients.

 

Specifications/standards

Specifications against which commercial products are judged for quality. Specifications of several fertilizers have been developed in different countries.

For purchasing fertilizers from international and/or national markets, Specifications have to be indicated. Prices of specific type of fertilizer may differ according to the required quality and specification.

 

Specifications for Commonly used Fertilizers (Word Document)

 

UREA (Free flowing)

  • Moisture content by weight: maximum 1%
  • Total nitrogen content by weight (on dry basis): minimum 46%
  • Biuret content by weight: maximum 1.5%
  • Particle size: Not less than 90% of the material shall pass through 2.8 mm IS sieve and be retained on 1 mm IS sieve.  Not more than 5% shall be below 1 mm IS sieve
  • Packing: Packed in 50 kg (dry) capacity woven polypropylene bags with polyethylene inner lining. 4% empty bags to be supplied at no extra cost
  • Each bag to guarantee minimum product weight (net) as specified on the bag
  • Marking: FAO logo, product name, active ingredient(s), net and gross weight, Project No., P.O. No. and final destination

UREA (Granular)

NOTE: Only when specially requested (for machine application) as it is slightly more expensive than free flowing Urea

  • Moisture content by weight: maximum 1%
  • Total nitrogen content by weight (on dry basis): minimum 46%
  • Biuret content by weight: maximum 1.5%
  • Particle size: Not less than 90% of the material shall pass through 4 mm IS sieve and be retained on 2 mm IS sieve. Not more than 5% shall be below 1 mm IS sieve
  • Packing: Packed in 50 kg (dry) capacity woven polypropylene bags with polyethylene inner lining. 4% empty bags to be supplied at no extra cost
  • Each bag to guarantee minimum product weight (net) as specified on the bag
  • Marking: FAO logo, product name, active ingredient(s), net and gross weight, Project No., P.O. No. and final destination

AMMONIUM SULPHATE

  • Moisture content by weight: maximum 1%
  • Total nitrogen content by weight (on dry basis): minimum 20%
  • Free acidity (as H2SO4) by weight: maximum 0.025%
  • Sulphur (as S) by weight: minimum 23%
  • Particle size: Not less than 90% of the material shall pass through 2.8 mm IS sieve and be retained on 1 mm IS sieve. Not more than 5% shall be below 1 mm IS sieve
  • Packing: Packed in 50 kg (dry) capacity woven polypropylene bags with polyethylene inner lining. 4% empty bags to be supplied at no extra cost
  • Each bag to guarantee minimum product weight (net) as specified on the bag
  • Marking: FAO logo, product name, active ingredient(s), net and gross weight, Project No., P.O. No. and final destination

CALCIUM AMMONIUM NITRATE (CAN)

  • Moisture content by weight: maximum 1%
  • Total nitrogen content by weight (on dry basis): 26%
  • Ammoniacal nitrogen by weight: 50% of total nitrogen
  • Nitrate nitrogen by weight: 50% of total nitrogen
  • Calcium and/or magnesium carbonate by weight: minimum 18%
  • Particle size: Not less than 90% of the material shall pass through 4 mm IS sieve and be retained on 1 mm IS sieve. Not more than 5% shall be below 1 mm IS sieve
  • Packing: Packed in 50 kg (dry) capacity woven polypropylene bags with polyethylene inner lining. 4% empty bags to be supplied at no extra cost
  • Each bag to guarantee minimum product weight (net) as specified on the bag
  • Marking: FAO logo, product name, active ingredient(s), net and gross weight, Project No., P.O. No. and final destination

SINGLE SUPERPHOSPHATE (SSP) (Powdered)

  • Moisture content by weight: maximum 12%
  • Free phosphoric acid (as P2O5) by weight:  maximum 4%
  • Water soluble phosphate (as P2O5) by weight: minimum 15.8%
  • Sulphur (as S) by weight: minimum 11%
  • Packing: Packed in 50 kg (dry) capacity woven polypropylene bags with polyethylene inner lining. 4% empty bags to be supplied at no extra cost
  • Each bag to guarantee minimum product weight (net) as specified on the bag
  • Marking: FAO logo, product name, active ingredient(s), net and gross weight, Project No., P.O. No. and final destination

SINGLE SUPERPHOSPHATE (SSP) (Granular)

NOTE: Price may be slightly higher than powdered material. Quotations may be asked for both types and decision to be taken based on availability and price.

  • Moisture content by weight: maximum 5%
  • Free phosphoric acid (as P2O5) by weight:  maximum 4%
  • Water soluble phosphate (as P2O5) by weight: minimum 15.8%
  • Sulphur (as S) by weight: minimum 11%
  • Particle size: Not less than 90% of the material shall pass through 4 mm IS sieve and shall be retained on 1 mm IS sieve. Not more than 5% shall be below 1 mm                                        
  • Packing: Packed in 50 kg (dry) capacity woven polypropylene bags with polyethylene inner lining. 4% empty bags to be supplied at no extra cost
  • Each bag to guarantee minimum product weight (net) as specified on the bag
  • Marking: FAO logo, product name, active ingredient(s), net and gross weight, Project No., P.O. No. and final destination

TRIPLE SUPERPHOSPHATE (TSP)

  • Moisture content by weight: maximum 5%
  • Free phosphoric acid (as P2O5) by weight:  maximum 3%
  • Total phosphates (as P2O5) by weight: minimum 46%
  • Water soluble phosphate (as P2O5) by weight: minimum 42.5%
  • Particle size: Not less than 90% of the material shall pass through 4 mm IS sieve and shall be retained on 1 mm IS sieve. Not more than 5% shall be below 1 mm                                       
  • Packing: Packed in 50 kg (dry) capacity woven polypropylene bags with polyethylene inner lining. 4% empty bags to be supplied at no extra cost
  • Each bag to guarantee minimum product weight (net) as specified on the bag
  • Marking: FAO logo, product name, active ingredient(s), net and gross weight, Project No., P.O. No. and final destination

POTASSIUM CHLORIDE/MURIATE OF POTASH (MOP) (Crystalline powder)

  • Moisture content by weight: maximum 0.5%
  • Water soluble potash content (as K2O) by weight: minimum 60%
  • Sodium (as NaCl) by weight: maximum 3.5%
  • Particle size: Not less than 65 % of the material shall pass through 1.7 mm IS sieve and be retained on 0.25 mm IS sieve
  • Packing: Packed in 50 kg (dry) capacity woven polypropylene bags with polyethylene inner lining. 4% empty bags to be supplied at no extra cost
  • Each bag to guarantee minimum product weight (net) as specified on the bag
  • Marking: FAO logo, product name, active ingredient(s), net and gross weight, Project No., P.O. No. and final destination

POTASSIUM CHLORIDE/MURIATE OF POTASH (MOP) (Granular)

NOTE: Price may be slightly higher than crystalline powder material. Quotations may be asked for both types and decision to be taken based on availability and price.

  • Moisture content by weight: maximum 0.5%
  • Water soluble potash content (as K2O) by weight: minimum 60%
  • Sodium (as NaCl) by weight: maximum 3.5%
  • Magnesium (as MgCl2) by weight: maximum 1%
  • Particle size: Not less than 90% of the material shall pass through 3.35 mm IS sieve and be retained on 1 mm IS sieve. Not more than 5% should be below 1 mm size.
  • Packing: Packed in 50 kg (dry) capacity woven polypropylene bags with polyethylene inner lining. 4% empty bags to be supplied at no extra cost
  • Each bag to guarantee minimum product weight (net) as specified on the bag
  • Marking: FAO logo, product name, active ingredient(s), net and gross weight, Project No., P.O. No. and final destination

POTASSIUM SULPHATE/SULPHATE OF POTASH (SOP)

  • Moisture content by weight: maximum 1.5%
  • Potash content (as K2O) by weight: minimum 50%
  • Total chlorides (as Cl) by weight: maximum 2.5%
  • Sodium (as NaCl) by weight: maximum 2%
  • Sulphur (as S) by weight: minimum 17.5%
  • Particle size: Not less than 65 % of the material shall pass through 1.7 mm IS sieve and be retained on 0.25 mm IS sieve
  • Packing: Packed in 50 kg (dry) capacity woven polypropylene bags with   polyethylene inner lining. 4% empty bags to be supplied at no extra cost
  • Each bag to guarantee minimum product weight (net) as specified on the bag
  • Marking: FAO logo, product name, active ingredient(s), net and gross weight, Project     No., P.O. No. and final destination

DIAMMONIUM PHOSPHATE (DAP)

  • Moisture content by weight: maximum 1.5%
  • Total nitrogen content by weight (on dry basis): minimum 18%
  • Neutral ammonium citrate soluble phosphate (as P2O5) content by weight: minimum 46%
  • Water soluble phosphate (as P2O5) content by weight: minimum 41%
  • Particle size: Not less than 90% of the material shall pass through 4 mm IS sieve and be retained on 1 mm IS sieve. Not more than 5% shall be below 1 mm size
  • Packing: Packed in 50 kg (dry) capacity woven polypropylene bags with polyethylene inner lining. 4% empty bags to be supplied at no extra cos.
  • Each bag to guarantee minimum product weight (net) as specified on the bag
  • Marking: FAO logo, product name, active ingredient(s), net and gross weight, Project No., P.O. No. and final destination

NPK COMPLEX 15-15-15

  • Moisture content by weight: maximum 1.5%
  • Total nitrogen content by weight (on dry basis): minimum 15%
  • Neutral ammonium citrate soluble phosphate (as P2O5) content by weight: minimum 15%
  • Water soluble phosphate (as P2O5) content by weight: minimum 12% 
  • Water soluble potash (as K2O) content by weight: minimum 15% 
  • Particle size: Not less than 90% of the material shall pass through 4 mm IS sieve and be retained on 1 mm IS sieve. Not more than 5% shall be below 1 mm size
  • Packing: Packed in 50 kg (dry) capacity woven polypropylene bags with polyethylene inner lining. 4% empty bags to be supplied at no extra cost
  • Each bag to guarantee minimum product weight (net) as specified on the bag
  • Marking: FAO logo, product name, active ingredient(s), net and gross weight, Project No., P.O. No. and final destination

NPK COMPLEX 17-17-17

  • Moisture content by weight: maximum 1.5%
  • Total nitrogen content by weight (on dry basis): minimum 17%
  • Neutral ammonium citrate soluble phosphate (as P2O5) content by weight: minimum 17%
  • Water soluble phosphate (as P2O5) content by weight: minimum 13.6%
  • Water soluble potash (as K2O) content by weight: minimum 17%
  • Particle size: Not less than 90% of the material shall pass through 4 mm IS sieve and be retained on 1 mm IS sieve. Not more than 5% shall be below 1 mm size
  • Packing: Packed in 50 kg (dry) capacity woven polypropylene bags with polyethylene inner lining. 4% empty bags to be supplied at no extra cost
  • Each bag to guarantee minimum product weight (net) as specified on the bag
  • Marking: FAO logo, product name, active ingredient(s), net and gross weight, Project No., P.O. No. and final destination

NPK COMPLEX 19-19-19

NOTE:  All other NPK complex grades will follow the same rule, particularly water soluble phosphate content should be 85% (minimum) of the neutral ammonium  citrate soluble phosphate content

  • Moisture content by weight: maximum 1.5%
  • Total nitrogen content by weight (on dry basis): minimum 19%
  • Neutral ammonium citrate soluble phosphate (as P2O5) content by weight: minimum 19%
  • Water soluble phosphate (as P2O5) content by weight: minimum 15.2%
  • Water soluble potash (as K2O) content by weight: minimum 19%
  • Particle size: Not less than 90% of the material shall pass through 4 mm IS sieve and be retained on 1 mm IS sieve. Not more than 5% shall be below 1 mm size
  • Packing: Packed in 50 kg (dry) capacity woven polypropylene bags with polyethylene inner lining. 4% empty bags to be supplied at no extra cost
  • Each bag to guarantee minimum product weight (net) as specified on the bag
  • Marking: FAO logo, product name, active ingredient(s), net and gross weight, Project No., P.O. No. and final destination

2. Micronutrient Fertilizers

ZINC SULPHATE

  • Zinc (as Zn) content by weight: minimum 21%                                             
  • Sulphur (as S) content by weight: minimum 10%                                         
  • Lead (as Pb) content by weight: maximum 003%                                    
  • Copper (as Cu) content by weight: maximum 1%                                      
  • Magnesium (as Mg) content by weight: maximum 5%                             
  • Cadmium (as Cd) content by weight: maximum 0.0025%                          
  • Arsenic (as As) content by weight: maximum 0.01%
  • Matter insoluble in water by weight: maximum 1%
  • pH: not less than 4
  • Form: free flowing powder

CHELATED Zn, AS Zn-EDTA

  • Zinc content (expressed as Zn) by weight in the form of Zn-EDTA complex: minimum 12%      
  • Lead (as Pb) content by weight: maximum 0.003%                                         
  • H: 6.0 – 6.5
  • Form: free flowing crystalline/powder

MANGANASE SULPHATE

  • Manganese (as Mn) content by weight: minimum 30.5%                              
  • Sulphur (as S) content by weight: minimum 17%                                               
  • Lead (as Pb) content by weight: maximum 0.003%                                           
  • Copper (as Cu) content by weight: maximum 0.1%                                           
  • Magnesium (as Mg) content by weight: maximum 2%
  • Matter insoluble in water by weight: maximum 1%·    
  • pH: not less than 3.75 
  • Form: free flowing powder                                                     

BORAX (SODIUM TETRABORATE)

  • Boron (as B) content by weight: minimum 10.5%    
  • Lead (as Pb) content by weight: maximum 0.003% 
  • Matter insoluble in water by weight: maximum 1%
  • pH: 9.0-9.5Form: free flowing powder

COPPER SULPHATE

  • Copper (as Cu) content by weight: minimum 24%    
  • Sulphur (as S) content by weight: minimum 12%
  • Soluble iron and aluminium compounds (expressed as Fe) content by weight: maximum 0.5% 
  • Lead (as Pb) content by weight: maximum 0.003%
  • Matter insoluble in water by weight: maximum 1%
  • pH: not less than 3
  • Form: free flowing powder/granular                                       

FERROUS SULPHATE

  • Ferrous iron (as Fe) content by weight: minimum 19%
  • Sulphur (as S) content by weight: minimum 10.5%
  • Free acid (as H2SO4) content by weight: maximum 1%
  • Ferric iron (as Fe) content by weight: maximum 0.5% 
  • Lead (as Pb) content by weight: maximum 0.003%
  • Matter insoluble in water by weight: maximum 1%
  • PH: not less than 3.5
  • Form: free flowing powder                                                          

CHELATED IRON, AS Fe-EDTA

  • Iron content (expressed as Fe) by weight in the form of Fe-EDTA complex: minimum 12%      
  • Lead (as Pb) content by weight: maximum 0.003%                                        
  • pH: 5.5 – 6.5
  • Form: free flowing crystalline/powder

AMMONIUM MOLYBDATE

  • Molybdenum (as Mo) content by weight: minimum 52% 
  • Lead (as Pb) content by weight: maximum 0.003%
  • Matter insoluble in water by weight: maximum 1%
  • pH: 5.0-5.5
  • Form: free flowing crystalline/powder

 

3. Rock Phosphate (RP)/Phosphate Rock (PR), for Direct Application

  • Total phosphates (as P2O5) content by weight: between 15-35% depending on source
  • Cadmium (as Cd) content by weight: maximum 27 mg/kg of RP
  • Particle size: Not less than 90% of the material shall pass through 0.15 mm IS sieve and the balance shall pass through 0.25 mm IS sieve

Global rock phosphate deposits and their quality 

 

4. Organic Manures

Quality of organic manures vary widely, depending on the materials used. However, basic criteria to consider suitability of the material as a nutrient source are:

  • Organic matter content by weight: minimum 30%
  • Organic carbon content by weight: minimum 12%
  • Total nutrients (N+ P2O5+ K2O) content by weight: minimum 5%

Subject to doubt and availability of analytical facilities, contents of following heavy metals should be checked:

  • Arsenic (As) content by weight: maximum 10 mg/kg
  • Cadmium (Cd) content by weight: maximum 5 mg/kg
  • Cromium (Cr) content by weight: maximum 50 mg/kg
  • Copper (Cu) content by weight: maximum 300 mg/kg
  • Lead (Pb) content by weight: maximum 100 mg/kg

Core Themes